Hot tapping is the technique to make a connection to a pipeline without interrupting or emptying the product inside the pipeline, employing an under-pressure drilling machine to create an opening in the pipeline. The drilling machine consists of a mechanically-driven boring bar with a cutting tool attached, a temporary or permanent valve depending on requirements, and a welted or bolted tee assembly which contains the system pressure and includes the branched outlet.
Line Stopping is an effective shut-off to pressurized pipes and vessels. This is used to isolate systems for repair or modifications. A size on size hot tapping connection via a fitting is first performed, which includes a branched outlet allowing the temporary valve to be recovered once the operation is complete. A plugging head is then inserted into the line by an actuator. The plugging head is then rotated and locked into position, blocking the line pressure.